The Riedel Vinum Extreme series wine glasses was designed to enhance the experience of the finest New World wines. The Riedel Vinum Extreme diamond shaped bowls showcase the special qualities of the bouquets that send sommeliers to ecstasy and make enthusiasts into connoisseurs. The Riedel Vinum Extreme series wine glasses are executed in lead crystal, hand blown in Bavaria Germany. They are dishwasher safe, but hand-washing is recommended for all fine Riedel glassware.